Senior Software Engineer, Customer Agent

## Responsibilities - Design, build, and scale systems that power intelligent workflows, conversational experiences, tools integrations, retrieval systems, onboarding flows, observability, and multi-channel customer engagement. - Help develop foundational platform capabilities and customer-facing experiences that enable brands to launch, customize, and continuously improve their own highly-configurable AI agents. - Tackle complex technical and product challenges, develop multiple solution paths, and evaluate business and architectural trade-offs to determine the best approach. - Act as a technical leader and mentor, driving engineering quality, execution, and decision-making across projects. - Deploy well-designed, thoroughly tested solutions that prioritize reliability, scalability, and customer impact. - Think holistically about customer outcomes, collaborate deeply across engineering, product, design, data science, and go-to-market teams, and push beyond traditional role boundaries to help the team move faster. - Ship high-quality systems quickly, contribute to foundational platform decisions, improve the intelligence and reliability of our agent experiences, and help define how AI-powered customer engagement evolves at Klaviyo. ## Requirements - A proven track record of building high-quality products and systems, with pride in writing clean, maintainable, high-quality code. - 7+ years of experience in a software engineering role. - Strong experience developing end-to-end software solutions or extensive experience across both front-end and back-end technologies. - Experience building scalable, customer-facing systems in fast-moving product environments. - Experience leading projects and being accountable for technical and business outcomes. - Experience mentoring team members or driving initiatives that help the team grow and learn new skills. - Experience conducting code reviews and maintaining a robust testing and deployment cycle. - Curiosity and enthusiasm for AI-native product development, including practical experience experimenting with LLMs, AI tooling, or agentic workflows in professional or personal projects. - Excitement about leveraging AI to improve engineering velocity, customer experiences, and operational workflows. - A strong product mindset and willingness to collaborate cross-functionally to solve ambiguous problems with urgency and pragmatism. ## Nice to Have - Skills with Python and related technologies. - Skills with React and related technologies. - Experience building conversational AI systems, workflow engines, or agentic platforms. - Experience with retrieval systems, embeddings, eval frameworks, or LLM orchestration patterns. - Experience building cloud-native solutions, ideally with AWS. - Experience developing customer support, commerce, marketing, or customer data software solutions. - Experience with machine learning systems or AI infrastructure. - Experience building multi-tenant or highly configurable SaaS platforms. - Familiarity with observability, tracing, experimentation, or AI quality/evaluation tooling. ## Benefits - At Klaviyo, we value the unique backgrounds, experiences and perspectives each Klaviyo (we call ourselves Klaviyos) brings to our workplace each and every day. We believe everyone deserves a fair shot at success and appreciate the experiences each person brings beyond the traditional job requirements. If you’re a close but not exact match with the description, we hope you’ll still consider applying. Want to learn more about life at Klaviyo? Visit klaviyo.com/careers to see how we empower creators to own their own destiny.